The invention relates to a boom arm for a concrete-distributing boom, having an elongate box-profile support which is formed, at least sectionally, from two flanges and two webs connecting the flanges laterally and which, at an end portion, exhibits two points of articulation which are spaced apart from one another in the longitudinal direction of the arm and are intended for the articulation of a hydraulic pivot drive, and having a sealing-partition arrangement for sealing a cavity region of the box-profile support, at least in the region of flange openings at the points of articulation. The invention further relates to a concrete-distributing boom having at least one boom arm of this kind.
In the articulation region, the respective pivot drive is firstly connected to mast arms of concrete-distributing booms and secondly the arms must be connected to one another. These both occasionally require the opening of the box-profile support. In order to prevent water from penetrating the cavity region of the arm, the openings must be closed again. In practice, sealing partitions that have hitherto been separated from one another are installed for each opening region. A trough is thereby created beneath the drive cylinder, in which water or ice and dirt can accumulate. These accumulations lead to additional loads and can cause damage to the support structure. To remedy the situation, conventional designs provide a procedure in which a hole is introduced into the web or flange plate and a pipe is welded in. This, in turn, causes a high notch effect in the components and usually leads to additional weight.